1. Field of the Invention
The present invention relates to a method and apparatus for aligning drill pipe or tubing utilizing novel tool joints or end connections. The present invention involves a method and apparatus for assuring that adjacent sections of drill pipe or tubing mate with each other the same way each time that they are put together.
2. The Prior Art
One of the problems in directional drilling is determining what direction the drilling device is pointing at the bottom of the well. Is it pointing North, East, South or West? Of course, if you could put the drill string sections together the same way each time such that they were tightened precisely the same amount, then one would expect that the directional drilling device at the bottom would be oriented in the same direction every time. However, it is not possible to tighten drill string sections precisely the same amount.
The same considerations hold true for tubing (as opposed to drill pipe) in that it sometimes becomes desirable to know in what direction a certain section of the tubing is oriented; for example, in the case of tubing conveyed perforating guns which are to make holes in casing. It may be desirable to know the direction in which the perforating gun is oriented prior to the commencement of the perforation operation. The present invention has a unique application to the use of any downhole tool which is attached to either a drill pipe section or a tubing section where the orientation of this downhole tool is important for the purpose of the operation in which the downhole tool is involved.
A preliminary search was conducted on the present invention and the following listed patents represent the results of the search:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 745,842 Hock, et al. 12-01-03 1,547,759 Journeay 07-28-25 1,780,712 Little 11-04-30 2,490,316 Ostrak 12-06-49 4,821,818 Mefferd 04-18-89 ______________________________________
Hock U.S. Pat. No. 745,842 shows a drill pipe wherein a shoulder 5 is provided with a sleeve 3 surrounding the adjacent pipe sections between the shoulders.
Journeay U.S. Pat. No. 1,547,759 shows a tool joint where adjacent pipe sections are provided with interlocking tongues 14 and grooves 13. However, in the Journeay patent there are four tongues and four grooves, all symmetrically arranged; therefore, it would be possible to place the adjacent pipe sections in four different relative angular relationships.
Little U.S. Pat. 1,780,713 is a flexible coupling for electrical fixtures and has nothing to do with drill pipe or the like.
Ostrak U.S. Pat. No. 2,490,316 is also an electrical connector. This patent shows adjacent electrical cables intermating with angled members. However, this patent has nothing whatever to do with drill pipe.
Mefferd U.S. Pat. No. 4,821,818 relates to an auger for drilling holes in the ground. This patent is similar to the Joumeay patent discussed above. In FIG. 3 of Mefferd, the mating ends of two sections is shown as each having six projections 40 and six indentations 42. These projections and indentations are all symmetrical so that it would be possible to obtain six different relative angular positions of one section with an adjacent mating section.